For seedlings whose lives began on a sunny windowsill, the vegetable patch is full of extreme conditions. Before they can handle the wind, rain and strong sun of the great outdoors, tender young plants need a period of gradual adjustment. The simple but crucial process of acclimating seedlings to life in the garden is called hardening off.

Begin hardening off your seedlings about a week before their transplant date. Set the containers (whether flats or individual pots) in a sheltered, shady spot outdoors. A covered porch is an ideal starter spot, so is a table or bench under a leafy tree. Bring the plants back inside at night, and bring them in at any time of day if the weather turns cold, windy or rainy. Expose the plants gradually to more sun. After two or three days, you can safely keep them in the sun for half a day, then return them to the shade. By the end of the week they'll be tough enough to soak up the rays all day.

Transplant the seedlings to the garden on an overcast day to ease the shock of transition from pot to ground.

If you have already planted your seedlings into the garden without hardening them off, you'll need to provide some shelter from hot afternoon sunshine. Drive a few stakes into the ground and tack some sun screen or Remay row cover fabric onto the tops of the stakes to shade your plants from noon on. Move the screening to provide more and more sunshine. The process should take about a week. Good luck with your tomato plants!